ophunzitsidwa Pangani ECG Yogwira Ntchito Ndi Kukonzekera Mwadzidzidzi kwa Biosignal
Pangani ECG Yogwira Ntchito Ndi Kukonzekera Mwadzidzidzi kwa Biosignal
Pulojekitiyi imaphatikiza zonse zomwe zaphunziridwa semesita iyi ndikuzigwiritsa ntchito pa ntchito imodzi. Ntchito yathu ndikupanga dera lomwe limatha kugwiritsidwa ntchito ngati electrocardiogram (ECG) pogwiritsa ntchito zida. amplifier, lowpass fyuluta, ndi notch filter. ECG imagwiritsa ntchito maelekitirodi omwe amaikidwa pa munthu kuti ayese ndikuwonetsa ntchito ya mtima. Kuwerengera kudapangidwa kutengera mtima wamunthu wachikulire, ndipo zoyambira zoyambira zidapangidwa pa LTSpice kuti zitsimikizire kupindula ndi mafupipafupi. Zolinga za polojekitiyi ndi izi:
- Gwiritsani ntchito luso la zida zomwe mwaphunzira mu labotale semesita iyi
- Pangani, pangani, ndikutsimikizirani magwiridwe antchito a chipangizo chotengera ma siginecha
- Tsimikizirani chipangizocho pamutu wamunthu
Zothandizira:
- LTSpice simulator (kapena mapulogalamu ofanana) Breadboard
- Zosiyanasiyana resistors
- Ma capacitors osiyanasiyana
- Opamps
- Mawaya a electrode
- Lowetsani voltagndi gwero
- Chipangizo choyezera kutulutsa mphamvutage (ie oscilloscope)
Gawo 1: Pangani Mawerengero a Chigawo Chilichonse Chozungulira
Zithunzi pamwambapa zikuwonetsa kuwerengera kwa dera lililonse. Pansipa, ikufotokoza zambiri za zigawo ndi kuwerengera kochitidwa.
Zida Ampwotsatsa
Chida ampLifier, kapena IA, imathandizira kupereka phindu lalikulu pazizindikiro zotsika. Zimathandizira kukulitsa kukula kwa siginecha kuti ziwonekere komanso mawonekedwe ake azitha kuwunikidwa.
Powerengera, tidasankha mitundu iwiri yodzitchinjiriza ya R1 ndi R2, yomwe ndi 5 kΩ ndi 10 kΩ, motsatana. Tikufunanso kuti phindu likhale 1000 kuti chizindikirocho chikhale chosavuta kusanthula. Chiŵerengero cha R3 ndi R4 chimathetsedwa ndi zotsatirazi:
Vout / (Vin1 – Vin2) = [1 + (2*R2/R1)] * (R4/R3) –> R4/R3 = 1000 / [1 + 2*(10) / (5)] –> R4/ R3 = 200
Kenako tidagwiritsa ntchito chiŵerengerocho kuti tisankhe mtengo uliwonse wa resistor. Ma values ndi awa:
R3 = 1 kΩ
Sefa ya Notch
Fyuluta ya notch imachepetsa ma siginecha mkati mwa kagulu kakang'ono ka ma frequency kapena imachotsa ma frequency amodzi. Mafupipafupi omwe tikufuna kuchotsa pankhaniyi ndi 60 Hz chifukwa phokoso lalikulu lopangidwa ndi zida zamagetsi limakhala pafupipafupi. AQ factor ndi chiŵerengero cha mafupipafupi apakati ku bandwidth, ndipo imathandizanso kufotokozera mawonekedwe a chiwembu. Chinthu chokulirapo cha Q chimabweretsa kuyimitsidwa kocheperako. Powerengera, tikhala tikugwiritsa ntchito mtengo wa Q wa 8.
Tinasankha kusankha ma capacitor omwe tinali nawo. Choncho, C1 = C2 = 0.1 uF, ndi C2 = 0.2 uF.
Ma equation omwe tikhala tikugwiritsa ntchito powerengera R1, R2, ndi R3 ndi awa:
R1 = 1 / (4*pi*Q*f*C1) = 1 / (4*pi*8*60*0.1E-6) = 1.6 kΩ
R2 = (2*Q) / (2*pi*f*C1) = (2*8) / (2*pi*60*0.1E-6) = 424 kΩ
R3 = (R1*R2) / (R1 + R2) = (1.6*424) / (1.6 + 424) = 1.6 kΩ
Zosefera za Lowpass
Sefa yotsika imachepetsa ma frequency apamwamba pomwe imalola ma frequency otsika kudutsa. Kuthamanga kwafupipafupi kudzakhala ndi mtengo wa 150 Hz chifukwa ndilo mtengo wolondola wa ECG kwa akuluakulu. Komanso phindu (K mtengo) lidzakhala 1, ndipo zosinthika a ndi b ndi 1.414214 ndi 1, motsatana.
Tinasankha C1 kuti ifanane ndi 68 nF chifukwa tinali ndi capacitor. Kuti nd C2 tigwiritse ntchito equation yotsatirayi:
C2 >= (C2*4*b) / [a^2 + 4*b(K-1)] = (68E-9*4*1) / [1.414214^2 + 4*1(1-1)] –> C2>= 1.36E-7
Chifukwa chake, tidasankha C2 kukhala yofanana ndi 0.15 uF
Kuti tiwerengere mitundu iwiri ya resistor, tinayenera kugwiritsa ntchito ma equations awa:
R1 = 2 / (2*pi*f*[a*C2 + sqrt([a^2 + 4*b(K-1)]*C2^2 – 4*b*C1*C2)] = 7.7 kΩ
R2 = 1 / (b*C1*C2*R1*(2*pi*f)^2) = 14.4 kΩ
Gawo 2: Pangani Schematics pa LTSpice
Zida zonse zitatu zidapangidwa ndikuyendetsedwa payekhapayekha pa LTSpice ndi kusanthula kwa AC. Makhalidwe omwe amagwiritsidwa ntchito ndi omwe tidawerengera mu gawo 1.
Gawo 3: Pangani Chida Ampli- zi
Tinapanga zida amplifier pa bolodi la mkate potsatira dongosolo la LTSpice. Ikangomangidwa, zolowetsa (zachikasu) ndi zotuluka (zobiriwira) voltages adawonetsedwa. Mzere wobiriwira umangokhala ndi phindu la 743.5X poyerekeza ndi mzere wachikasu.
Gawo 4: Pangani Sefa ya Notch
Kenako, tidapanga fyuluta ya notch pa bolodi lazakudya kutengera dongosolo lomwe linapangidwa pa LTSpice. Inamangidwa pafupi ndi dera la IA. Kenako tinajambula input and output voltage amawerengera pama frequency osiyanasiyana kuti adziwe kukula kwake. Kenaka, tinajambula kukula kwa magnitude vs. pafupipafupi pa chiwembucho kuti tifanizire ndi LTSpice kayeseleledwe. Zomwe tidasintha zinali za C3 ndi R2 zomwe ndi 0.22 uF ndi 430 kΩ, motsatana. Apanso, pafupipafupi yomwe ikuchotsa ndi 60 Hz.
Gawo 5: Pangani Sefa ya Lowpass
Kenako tidapanga zosefera zotsika pa bolodi lazakudya kutengera dongosolo la LTSpice pafupi ndi fyuluta ya notch. Kenako tidalemba zolowetsa ndi zotulutsatages pa ma frequency osiyanasiyana kuti adziwe kukula kwake. Kenako, tidakonza kukula kwake ndi kuchuluka kwake kuti tifananize ndi LTSpice simulation. Mtengo wokha womwe tidasintha pa fyulutayi ndi C2 yomwe ndi 0.15 uF. Mafupipafupi omwe timawatsimikizira ndi 150 Hz.
Gawo 6: Mayesero pa Nkhani ya Munthu
Choyamba, gwirizanitsani zigawo zitatu za dera limodzi. Kenako, yesani ndi kugunda kwamtima kofananira kuti muwonetsetse kuti zonse zikuyenda. Kenaka, ikani maelekitirodi pa munthuyo kuti zabwino zikhale kudzanja lamanja, zoipa zili kumanzere, ndipo pansi pa bondo lakumanja. Munthuyo akakonzeka, gwirizanitsani batire ya 9V kuti muyambitse opamps ndikuwonetsa chizindikiro chotuluka. Dziwani kuti munthuyo ayenera kukhala chete kwa masekondi pafupifupi 10 kuti awerenge molondola.
Zikomo, mwapanga bwino ECG yokhazikika!
Zolemba / Zothandizira
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ophunzitsidwa Pangani ECG Yogwira Ntchito Ndi Kukonzekera Mwadzidzidzi kwa Biosignal [pdf] Malangizo Pangani ECG Yogwira Ntchito Ndi Kukonzekera Mwadzidzidzi kwa Biosignal, Pangani ECG Yogwira Ntchito, ECG Yogwira Ntchito, Kukonzekera kwa Biosignal |
